Classification of Psychological Disorders

Classification Systems The DSM-5 is the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (American Psychiatric Association, 2013). It is currently the most common means of classifying mental disorders used in the United States and, along with the International Classification of Diseases, 10th Revision (ICD-10) (World Health Organization, 1992), one of the most widely used classification systems for mental disorders around the world.

Contents of the DSM The DSM-5 contains diagnostic criteria and codes for 19 specific categories of mental disorders and additional codes for conditions (often called V-codes) that may be a focus of clinical attention not considered mental disorders. These would include problems such as sibling relational problems, religious or spiritual problems, or extreme poverty.

Organization of the DSM The categories of the DSM are laid out in a general developmental fashion, with categories of disorders typically seen early in the lifespan described first, and those usually expressed later in the lifespan later. Likewise, disorders within categories are also presented in a somewhat developmental sequence (young to old).

International Classification of Disease The International Classification of Diseases (ICD) is published by the World Health Organization. This manual is the most commonly used system for the classification of all diseases. It has a chapter devoted to the classification of mental and behavioral disorders. The current DSM uses coding from the current ICD-9-CM and the upcoming ICD-10-CM, and it has an organizational structure that reflects the anticipated structure of the ICD-11, due to be published sometime later this year. Though the DSM and ICD organizational systems are not identical, there is and will continue to be a great deal of correspondence between the two systems.

Understanding Classification The classification of problems is difficult because the ways humans may experience and express problems are nearly limitless. Thus, classification provides descriptions of the most common ways humans express problems. These descriptions are best understood as prototypes (best examples of problems).

Criticisms of the DSM There are many criticisms of the DSM as a classification tool. First among them is that the system is based on a biomedical model of problems (e.g., the term diagnostic). Another major criticism concerns the categorical nature of classification. Though in reality individual problems are best described dimensionally (more or less), the DSM is a categorical system (in or out). This categorical system is maintained because it is a traditional form of classification in medicine and because it is easier for clinicians to understand and use.

The categorical nature of the DSM tends to increase inter- rater reliability, but is more questionable with regard to issues of validity. Further, it creates problems such as reification of the categories (making the categories seem like real entities), exacerbates problems such as labeling, and increases the likelihood that a diagnostic label becomes integrated into the schemas of others and an individual’s own self-schema becomes stigmatic.

Categories are descriptions of problems and not explanations for them Categories are descriptions of problems and not explanations for them. For example, bulimia nervosa describes a problem in which an individual binge eats and is involved in compensatory behavior. It does not mean that a person acts that way because of bulimia nervosa. Psychological disorders are complex and (as outlined previously) are explained in different ways by various theoretical approaches.

Modifications The DSM-5 attempts to address some of these issues by incorporating more dimensional aspects. This has been done in a variety of ways, for example by broadening some categories of disorders (e.g., autism spectrum disorder) and allowing for coding of severity of many problems along with the use of specifiers (e.g., major depressive disorder). Despite these additions, the DSM has essentially maintained its categorical nature.

Important things to remember about classification Psychological disorders are classified only if the problems interfere with the person’s life in some “clinically significant” (American Psychiatric Association, 2013) way. Typically, a mental health professional determines this clinical significance based on the degree of the individual’s suffering and/or the reports of others close to the individual. Psychological problems are complex and have biological, psychological, and sociocultural aspects. Thus, questions like “Is schizophrenia genetic?” denote an oversimplification of the complexities of the problems that together are known as schizophrenia.

Problems exist at different levels of severity, and the combinations of factors that might produce a problem for one person could be different from the factors that might produce similar problems in others. The American Psychiatric Association (2013) makes it clear that psychological disorders “are defined in relation to culture, social and familial norms and values” (p. 14). Thus, it is important to understand the particular cultural background of an individual to understand the type and severity of the problem a person may be experiencing. Additionally, people’s different ages, cultural/ethnic backgrounds, and sexual orientation can relate to issues of mental health.

Culture and Gender Factors such as culture and gender can have an impact on the way individuals experience problems. For example, a person’s particular culture can influence how that person exhibits the problems they do. Examples of this may be the increase in numbers of people exhibiting dissociative identity disorders, eating disorders, or attention-deficit hyperactivity disorders in the United States or the existence of even more culture-specific disorders such as susto. Susto is an anxiety disorder found among people in Central and South America that is supposedly caused by having contact with supernatural beings or being the victim of black magic. It is important to remember that culture and gender are not specific single causes of psychological problems, but they can play a role in the development, experience, and expression of psychological disorders.